<?php
class Ws_Md24 {
	private static $instance;
	
	private function __construct() {
    
    }
	
	 public function get_instance() {
        if ( null == self::$instance ) {
            self::$instance = new self;
        }
        return self::$instance;
    } // end get_instance
 	
 	public function get_user_info() {
 		$json_data = json_encode("nvkhoa");
		echo $json_data;
 	}
}
Ws_Md24::get_instance();
?>